1998 3.0L Starter Randomly engages. HELP
#1
11-04-2007
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Location: La Quinta Ca
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1998 3.0L Starter Randomly engages. HELP
OK I did a search on the forum and did not come up with anything. The truck just started doing it one day. Sometimes the starter just decides to engage and crank the truck over. The key does not even have to be in the ignition. Some times it does when it is already running. Of course when it does this it grinds like crazy. Just like when you accidently bump the key when it's already running. The truck does not have any after market alarm or remote start installed now of in the history of this truck. Anyone have any ideas? Starter solenoid?? Which on this truck is part of the starter, which has been replaced before. Please shoot me some ideas
Thanks
Thanks
#4
11-05-2007
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#6
11-07-2007
Sure, Joe. Welcome to R-F.
There are two power wires to the starter, big Red (straight from the battery) and the Yellow w/ Light Blue stripe (YE/LB) which is the small wire controlling the solenoid.
Your symptom points to the YE/LB having power when it shouldn't, as if the key were turned to crank. This power comes from the starter relay which is controlled through the key/ignition switch, the DTR (in Park or Neutral only), the clutch pedal position jumper (I assume you have an automatic - clutch position switch if manual trans) to the starter relay coil. When that relay coil is energized, the relay closes and sends power to the solenoid on the YE/LB wire.
If you don't want to throw parts at it (smart of you) here's my troubleshooting plan for you:
Take a regular old toggle switch and some wire (same gage or bigger). Put that switch in line with the small wire to the starter (YE/LB) so that AFTER you start the vehicle, you can flip that switch to OFF and that YE/LB wire CANNOT put power to the starter until you flip the switch back ON again. (This is temporary - just for testing).
Drive it around like that waiting for the starter to do its trick with that switch open. If it DOES, replace the starter because you KNOW it didn't get the power to make it do that.
If that isn't something you're comfortable doing, swap the starter relay (in the battery junction box) with another just like it.
I can't fathom this simply being an ignition switch because you have to get the power through the contacts in the DTR (Digital Transmission Range Sensor) that are only closed in Park and Neutral. Another test you can try is will it crank the starter with the Tranny in Drive. If so, you still have to have TWO problems, a bad DTR AND a bad ignition switch causing your spurious starter engagement. Highly unlikely, but possible.
If yours is a manual transmission, you'd have to have a bad clutch pedal switch (which is detected by it cranking without pressing on the clutch - not proper operation) AND a bad ignition switch.
So, in my opinion, you either have a bad starter or a bad starter relay. The relay is cheaper (there is probably its twin used elsewhere, so a swap is free). My money is on the starter, unless it is doing the exact same thing that you previously replaced the starter for.
There are two power wires to the starter, big Red (straight from the battery) and the Yellow w/ Light Blue stripe (YE/LB) which is the small wire controlling the solenoid.
Your symptom points to the YE/LB having power when it shouldn't, as if the key were turned to crank. This power comes from the starter relay which is controlled through the key/ignition switch, the DTR (in Park or Neutral only), the clutch pedal position jumper (I assume you have an automatic - clutch position switch if manual trans) to the starter relay coil. When that relay coil is energized, the relay closes and sends power to the solenoid on the YE/LB wire.
If you don't want to throw parts at it (smart of you) here's my troubleshooting plan for you:
Take a regular old toggle switch and some wire (same gage or bigger). Put that switch in line with the small wire to the starter (YE/LB) so that AFTER you start the vehicle, you can flip that switch to OFF and that YE/LB wire CANNOT put power to the starter until you flip the switch back ON again. (This is temporary - just for testing).
Drive it around like that waiting for the starter to do its trick with that switch open. If it DOES, replace the starter because you KNOW it didn't get the power to make it do that.
If that isn't something you're comfortable doing, swap the starter relay (in the battery junction box) with another just like it.
I can't fathom this simply being an ignition switch because you have to get the power through the contacts in the DTR (Digital Transmission Range Sensor) that are only closed in Park and Neutral. Another test you can try is will it crank the starter with the Tranny in Drive. If so, you still have to have TWO problems, a bad DTR AND a bad ignition switch causing your spurious starter engagement. Highly unlikely, but possible.
If yours is a manual transmission, you'd have to have a bad clutch pedal switch (which is detected by it cranking without pressing on the clutch - not proper operation) AND a bad ignition switch.
So, in my opinion, you either have a bad starter or a bad starter relay. The relay is cheaper (there is probably its twin used elsewhere, so a swap is free). My money is on the starter, unless it is doing the exact same thing that you previously replaced the starter for.
#7
11-07-2007
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[QUOTE=Earl43P]
Thank you for the trouble shooting guide, I'll let you know what happens.
Sure, Joe. Welcome to R-F.
There are two power wires to the starter, big Red (straight from the battery) and the Yellow w/ Light Blue stripe (YE/LB) which is the small wire controlling the solenoid.
Your symptom points to the YE/LB having power when it shouldn't, as if the key were turned to crank. This power comes from the starter relay which is controlled through the key/ignition switch, the DTR (in Park or Neutral only), the clutch pedal position jumper (I assume you have an automatic - clutch position switch if manual trans) to the starter relay coil. When that relay coil is energized, the relay closes and sends power to the solenoid on the YE/LB wire.
If you don't want to throw parts at it (smart of you) here's my troubleshooting plan for you:
Take a regular old toggle switch and some wire (same gage or bigger). Put that switch in line with the small wire to the starter (YE/LB) so that AFTER you start the vehicle, you can flip that switch to OFF and that YE/LB wire CANNOT put power to the starter until you flip the switch back ON again. (This is temporary - just for testing).
Drive it around like that waiting for the starter to do its trick with that switch open. If it DOES, replace the starter because you KNOW it didn't get the power to make it do that.
If that isn't something you're comfortable doing, swap the starter relay (in the battery junction box) with another just like it. [quote/]
I can't fathom this simply being an ignition switch because you have to get the power through the contacts in the DTR (Digital Transmission Range Sensor) that are only closed in Park and Neutral. Another test you can try is will it crank the starter with the Tranny in Drive. If so, you still have to have TWO problems, a bad DTR AND a bad ignition switch causing your spurious starter engagement. Highly unlikely, but possible.
The truck did crank when it was running before so am gonna bet that it is either a relay or starter solenoid. When I get home today I will try to start the truck in Drive, If it does start then I know it is both the DTR and Ignition Switch. However I am gonna put my money on either the relay or starter soleniod. Like I said the starter is a over the counter parts house special.
If yours is a manual transmission, you'd have to have a bad clutch pedal switch (which is detected by it cranking without pressing on the clutch - not proper operation) AND a bad ignition switch.
The truck is a auto
So, in my opinion, you either have a bad starter or a bad starter relay. The relay is cheaper (there is probably its twin used elsewhere, so a swap is free). My money is on the starter, unless it is doing the exact same thing that you previously replaced the starter for.
There are two power wires to the starter, big Red (straight from the battery) and the Yellow w/ Light Blue stripe (YE/LB) which is the small wire controlling the solenoid.
Your symptom points to the YE/LB having power when it shouldn't, as if the key were turned to crank. This power comes from the starter relay which is controlled through the key/ignition switch, the DTR (in Park or Neutral only), the clutch pedal position jumper (I assume you have an automatic - clutch position switch if manual trans) to the starter relay coil. When that relay coil is energized, the relay closes and sends power to the solenoid on the YE/LB wire.
If you don't want to throw parts at it (smart of you) here's my troubleshooting plan for you:
Take a regular old toggle switch and some wire (same gage or bigger). Put that switch in line with the small wire to the starter (YE/LB) so that AFTER you start the vehicle, you can flip that switch to OFF and that YE/LB wire CANNOT put power to the starter until you flip the switch back ON again. (This is temporary - just for testing).
Drive it around like that waiting for the starter to do its trick with that switch open. If it DOES, replace the starter because you KNOW it didn't get the power to make it do that.
If that isn't something you're comfortable doing, swap the starter relay (in the battery junction box) with another just like it. [quote/]
I can't fathom this simply being an ignition switch because you have to get the power through the contacts in the DTR (Digital Transmission Range Sensor) that are only closed in Park and Neutral. Another test you can try is will it crank the starter with the Tranny in Drive. If so, you still have to have TWO problems, a bad DTR AND a bad ignition switch causing your spurious starter engagement. Highly unlikely, but possible.
The truck did crank when it was running before so am gonna bet that it is either a relay or starter solenoid. When I get home today I will try to start the truck in Drive, If it does start then I know it is both the DTR and Ignition Switch. However I am gonna put my money on either the relay or starter soleniod. Like I said the starter is a over the counter parts house special.
If yours is a manual transmission, you'd have to have a bad clutch pedal switch (which is detected by it cranking without pressing on the clutch - not proper operation) AND a bad ignition switch.
The truck is a auto
So, in my opinion, you either have a bad starter or a bad starter relay. The relay is cheaper (there is probably its twin used elsewhere, so a swap is free). My money is on the starter, unless it is doing the exact same thing that you previously replaced the starter for.
#8
11-08-2007
With the Auto, there is a jumper buried under the dash that bypasses where the Clutch Pedal Position connection would be made. Could be a handy spot to interrupt the voltage going to the coil of the starter relay, should you find that necessary.
You didn't comment on whether this is the exact same failure mode that the "parts house special" starter was replaced for. Regardless, I agree: it's either the relay or the starter. I haven't disassembled one of these Ford starters, but I've done many others. It could be a loose wire/connection inside the starter, shorting to the big red battery power connection.
I wouldn't be able to resist disassembling that starter to find out. But I'd also look really hard at the starter's connections and wiring for a chafing short between those two wires near the starter before I started unbolting the starter.
Good luck!
You didn't comment on whether this is the exact same failure mode that the "parts house special" starter was replaced for. Regardless, I agree: it's either the relay or the starter. I haven't disassembled one of these Ford starters, but I've done many others. It could be a loose wire/connection inside the starter, shorting to the big red battery power connection.
I wouldn't be able to resist disassembling that starter to find out. But I'd also look really hard at the starter's connections and wiring for a chafing short between those two wires near the starter before I started unbolting the starter.
Good luck!
#9
11-12-2007
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Well I got under the truck on Saturday to drop the starter. To my pleasant surprise I found that the main power wire to the starter and the activation wire that bolt on the the back of the starter where extremely close together. I don't think I could have gotten a paper between them. I lossened them and re clocked them and I am going to see what happens. Don't know how they got like that but they where close enough to where any bump in the road could have made them touch and engage the starter. Hopefully this is the cure! Easy fix.
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